Many service providers in North America, and particularly in the United States, offer a long distance service generally referred to as a "call-back" service. In that service, individuals residing or traveling in foreign countries are invited to take advantage of lower long distance rates available in North America by dialing a toll free number which alerts the service provider's system that the subscriber wishes to make a long distance call using North American facilities. The subscriber system captures the caller's telephone number from the Common Channel Signaling (CCS) call setup messages. As soon as the toll free call is received, it is terminated and the system initiates a call-back. When the subscriber answers the call-back, he is provided with a dial tone or prompt indicating that he may dial a number to which he wishes to place the long distance call. The subscriber then dials the digits required to complete the call. Since the call is completed over the facilities of the service provider, the subscriber pays the lower long distance rates applicable in North America. While this system is advantageous in terms of costs, it is awkward and time consuming to use because of the plurality of digits that must be dialed in order to effect call completion.
Computer telephony integration products are also known. For example, desktop call control applications for Windows.RTM.-based Personal Computer users are available which permit graphical access and control of the user's telephone handset and voice mailbox. Such applications may also automate the handling of inbound and outbound telephone calls. A shortcoming of such applications is that they do not leverage the switching power resident in the Switched Telephone Network (STN). Instead, they try to duplicate that switching power and thereby sacrifice efficiency.
It is likewise known to use a multimedia PC to complete Voice Over Internet Protocol (VoIP) calls using the Internet as a transport medium. Gateways have even been established in certain cities which permit VoIP calls to be completed to a regular telephone on the Switched Telephone Network (STN). The gateways convert VoIP packets to STN voice format, and vice/versa, after a dial-up connection is established with the regular telephone. While VoIP appears to be an attractive alternative to STN voice connections, it suffers from several disadvantages. Obviously, it extensively uses computer resources and access to the data network so that they are less available for other functions. Due to the current demand for bandwidth on the Internet, VoIP transmission quality is also frequently poor. Besides, multimedia PCs still represent only a small portion of the total PC devices in use, and a service directed to those PC users without multimedia PCs is beneficial.
There therefore exists a need for a method and apparatus which combine the enhanced functionality of computerized call control with the dependability and assured transmission quality of STN facilities and uses the inherent switching power resident in the STN.